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> module Calc where
> import Lexer
> import Result
>
> %{
>
> Terminal = Numeral {Int}
> | Addop {Op}
> | Mulop {Op}
> | LParen as "("
> | RParen as ")";
>
> Nonterminal = expr {Int}
> | term {Int}
> | factor {Int};
>
> expr {app op v1 v2} : expr {v1}, Addop {op}, term {v2};
> {e} | term {e};
> term {app op v1 v2} : term {v1}, Mulop {op}, factor {v2};
> {e} | factor {e};
> factor {n} : Numeral {n};
> {e} | "(", expr {e}, ")";
>
> }%
>
> frown _ = fail "syntax error"
|
